JTextField textField = new JTextField();
JRadioButton activeButton = new JRadioButton("Active");
JRadioButton inactiveButton = new JRadioButton("Inactive");
activeButton.addActionListener(new ActionListener()
{
    public void actionPerformed(ActionEvent e)
    {
        textField.setEditable(true);
    }
});
inactiveButton.addActionListener(new ActionListener()
{
    public void actionPerformed(ActionEvent e)
    {
        textField.setEditable(false);
    }
});